Fast and efficient RFID tag counting is an essential requirement for a lot of modern applications, particularly in high-density environments. This paper proposes an innovative algorithm designed to accelerate counting while maintaining compatibility with the EPCglobal Class 1 Generation 2 (C1G2) protocol. Relying on a single RN16 answer from each tag to validate its presence, the method speeds up counting by eliminating a full reader-tag communication, reducing processing time. The proposed method was validated using a software-defined radio (SDR) platform. Compared to the standardized protocol, our experiments demonstrated that up to four tags can be counted in the time required to identify a single tag, achieving approximately 77 % time savings across various data rates. This paper shows that the algorithm provides a feasible and scalable solution for RFID tag counting, incorporating collision information into its design to greatly improve counting speed, even in crowded environments.